Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 42:716–724, 2012
Copyright ꢀ Taylor & Francis Group, LLC
C
ISSN: 1553-3174 print / 1553-3182 online
DOI: 10.1080/15533174.2011.615780
Syntheses, Structures, and Properties of 3,3ꢀ-Dimethoxy-
2,2ꢀ-[(1,3-propylene)dioxybis(nitrilomethylidyne)]diphenol
and Its Ni(II) Cluster
Wen-kui Dong, Li Li, Yin-Xia Sun, Jun-Feng Tong, and Jian-chao Wu
School of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou, Gansu,
P. R. China
elemental Salen-type ligand (e.g., introduction of some func-
A new Salen-type bisoxime chelating ligand, 3,3ꢀ-dimethoxy-
2,2ꢀ-[(1,3-propylene)dioxybis(nitrilomethylidyne)]diphenol (H2L),
and its Ni(II) cluster, [{NiL(CH3CH2OH)}2(OAc)2Ni]·2CH3CH2
OH·CH3COCH3, have been synthesized and characterized by el-
emental analyses, FT-IR spectra, UV-vis spectra, 1H-NMR, molar
conductance measurements, and thermal properties. X-ray crys-
tallographic analyses reveal that the structure of the Ni(II) cluster
is as follows: two acetate groups coordinating to three metal(II) ions
through Ni–O–C–O–Ni bridges and four µ-phenoxo oxygen atoms
from two [NiL(CH3CH2OH)] units also coordinating to metal(II)
ions. In the cluster, two ethanol molecules coordinate to the two ter-
minal nickel(II) ions and form a trinuclear structure. Meanwhile,
the Ni–O–C–O–Ni and µ-phenoxo bridges play important roles in
assembling metal ions and ligands.
tional groups or substitution of some parts with appropriate
ones) are effective and inevitable. In particular, replacement of
some atoms of the ligand with other elements often changes its
properties drastically.[4,5] If an O-alkyl oxime moiety (-CH =
N-O-(CH2)n-O-N CH-) is used instead of the imine moiety, the
larger electronegativity of oxygen atoms is expected to strongly
affect the electronic properties of N2O2 coordination sphere,
which can lead to different and novel properties and structures
of the resulted complexes.[6,7]
Herein, in succession to our previous studies,[8,9] a new
Salen-type (Salen, N,N’-disalicylidenetrimethylenediamine)
bisoxime chelating ligand H2L and its trinuclear cluster
[{NiL(CH3CH2OH)}2(OAc)2Ni] · 2CH3CH2OH· CH3COCH3
have been synthesized and structurally characterized by X-ray
crystallography.
Keywords cluster, crystal structure, Salen-type ligand, spectroscopic
behavior, synthesis
EXPERIMENTAL
INTRODUCTION
Materials and Instruments
Transition metal complexes with N,N’-disalicylideneethy
lenediamine (Salen) ligand or its derivatives are extensively
investigated, not only because these series of complexes have
played a seminal role in the development of modern coordi-
nation chemistry, but they can also be used in the design and
construction of new magnetic materials and model for the metal
center of enzymes. Although some advance has been made in
the studies of Salen-Ni(II) complexes,[1–3] it still seems there
could be new and specific applications for such a unique group
of compounds. To change the structures or improve the func-
tions of the resulted complexes, chemical modifications of the
4-Methoxy-2-hydroxybenzaldehyde (≥98%) from Alfa Ae-
sar was used without further purification. The other reagents and
solvents were analytical grade reagents from Tianjin Chemical
Reagent Factory, and were used without further purification. El-
emental analyses for Ni was detected by an IRIS ER/S·WP-1
ICP atomic emission spectrometer. C, H, and N analyses were
carried out with a GmbH VariuoEL V3.00 automatic elemental
analyzer. FT-IR spectra were recorded on a VERTEX70 FT-IR
spectrophotometer, with samples prepared as KBr (500–4000
cm−1) and CsI (100–500 cm−1) pellets. UV–vis absorption
spectra were recorded on a Shimadzu UV-2550 spectrome-
ter. TG-DTA analyses were carried out at a heating rate of
5◦C/min on a ZRY-1P thermoanalyzer. H NMR spectra were
1
recorded on a Mercury-400BB spectrometer at room temper-
Received 8 December 2009; accepted 14 August 2011.
This work was supported by the Foundation of the Education De- ature using CDCl3 as solvent. X-ray single crystal structures
partment of Gansu Province (0904–11) and the ‘Jing Lan’ Talent En-
were obtained on a Rapid Auto Version 3.0 Rigaku RAXIS-
gineering Funds of Lanzhou Jiaotong University, which are gratefully
RAPID detector. Melting points were measured by the use of
acknowledged.
a microscopic melting point apparatus made in Beijing Taike
Address correspondence to Wen-Kui Dong, School of Chemical
Instrument Limited Company, and the thermometer was uncor-
rected. Molar conductance value measurements were carried
and Biological Engineering, Lanzhou Jiaotong University, Lanzhou
730070, P. R. China. E-mail: dongwk@126.com
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